What is the primary substance of plant cell walls

What initially causes a nerve impulse? release of enzymes out of the neuron movement of chemicals into the dendrites of the neuron pathogens attacking the dendrites of the neuron red blood cells bathing the neuron

All individuals have two alleles for a given trait. according to mendel's these alleles are passed down one each from both mother and father.

Select the correct answer from each drop-down menu proteins are